Projectile.



S. D. CUSHING.

PROJECTILE.

lou 'msn mm l 15.

Paten Nov. 9, 1915.

2 SHEETS-SHEET 1 .si D. CUSHING.

, vPROJICTILE.

APPLICATION FILED $58.19. |915.

2 SHEETS-SHEET 2.

21ml Q .E ,mi

Patented Nov. 9, 1915.

INvzN-ron Aran srarns PATENT ormon- .SAMUEL D. CIISHING, OF WESTMINSTER, LONDON,ENGLAND, ASSIGNOR TO JOHN B.

' SEMPLE, 0F SEWICKLEY, PENNSYLVANIA.

PROJECTIL. i

.Specification of Letters Patent.

Patented Nov.9, 1915.

.Y Appuaaon alea retruary 19, 1915. vsentira.9,407.

To'all whom it may concern.'

.Beit known that I, SAMUEL D. CUsHING, e'siding a lVestminster, in the county of `londonyl gland, a citizen of the United States, have invented or discovered certain new and useful Improvements in lProjectlles,

. of which improvements the following is a My invention relates to improvements in projectiles, and, more particularly, 1t has to (lo-with the ignition of the tracer material with which projectiles may be equipped.,

In order to ignite the tracer material, it

has been customary to utilize the motion of the projectile or the pressure of the propel? ling charge gases to operatea percussion x primer, or to rely upon the iash of disf charge of the propelling charge-either by its unimpededcontact with the tracer material `'or a more readily ignitible composition at the base thereof, .or by such contact attained through an aperture formed in a protectlve plate or shield by the pressure or heat of the propelling charge gases.

The chief object of the4 present invention iste provide a reliable and effective projectile tracer adapted to be rendered operative Without relying upon percussive action or exposing the combustible material to the flash of discharge or the direct pressure ofthe propelling charge gases. It Will be understood that, with a tracer having such characteristics, the density and composition or" the tracer material can be chosen to suit requirenients, 'vgitllout having to take into consideration the effect of the pressure or Alhfme of' the prcpelling chargegases upon it.

`According to the present invention the heat or" the propelling'charge gases 1s utiL `lized indirectly to effect the ignition of the propelling charge by a Wall of suiiicient 4strength to resist-. being fractured or destroyed by ,the heat or pressure, or the heat and pressure, of the propelling charge gases but suflicievntly' heat 'conductive to enable the heat f'o'f the `gases to rapidly penetrate the wall and produce an effect which directly or indirectly causes ignition of the tracer 'material.

.In order that the invention may be clearly understood and readily carried into effect, I will now describe the same more fully with reference to the accompanying drawings which illustrate various constructional embodimentsl of the invention.

Figure 1` is a longitudinal section of a projectile provided with one of my improved tracers. Figs. 2 to 10il illustrate various constructional modifications of the tracer. Fig.

llillustrates in longitudinal section a projectile having a tracer provided with one constructional form of the means I employ to prevent the Wadding or spacing disk in the cartridge case from preventing or delaying the ignition of the tracer. Fig. 11 is a detached view of the tracer of Fig 11 and in a position at right angles tothat o Fig. 11.

In all the figures like reference letters indicate similar parts.

A is the projectile; B isithe tracer body,

part of the plug C, leaving a wall c integral withthemain portion. The wall .c is sufciently strong to resist being :fractured or destroyed by the heat or pressure, or the combined heat and pressure, of the propelling charge gases which make contact with it when the gun is fired, but is suiliciently of the gases to rapidly lpenetrate and there by raise Vthe temperature of the material in the recess or pocket to its ignition point. The specific material of which lthis wall c is formed may vary. Copper may be used,

v thin and heat conductive to enable the heator brass, or other metal, or even non'metallic material. It is necessary; of course, that g, the wall withstand the ,impact'or rush of ,gases generated on the ring of' the projectile from a gun. Accordingly, given such gas pressure of' deter-minable intensity and given any specific material, and given a certain size for theori'ce to be covered, there will be for each material a certain admissible minimum thickness. Each material has its own heat conductivity, and the question in any given case is whether the material .selected when made of the minimumithickness permissible will in view of its conductivity afford passage of heat with sufficient rapidity and in sufiicient quantity to edectignition. As l have. said, copper 'and its alloys are serviceable. The burning vof the material in pocket C causes the ignition of the tracer material in the cell or chamber B. lt will be understood that, as

soon as the projectile leaves the gun, the plug C will be removed. to leaveethe tracer chamber unobstructed. This will ordinarily be accomplished thusz-VVhen the projectile leaves the guii the pressure of the propelling charge gases on the plug is relieved,

the internal pressure due to 'the burning of tracer material in the cell or chamber of the tracer will blow away the plug C and enable the flame or smoke of the tracer material to pass out at the mouth of the tracer chamber.

ln the constructional form of tracer shown'in Fig. 2, the recess or pocket'Q is formed by boring al hole through the plug C and providinga cover plate 0 to serve as the above mentioned thin wall, the said plate being kept in position in any convenient manner, as for instance by slightly beveling the edge of the plate and forcing the adjacent metal of the plug to overlap the beveled edge. Thus seculrd, the plate will resist being forced inward but will be blown ofi-rearwardly with comparative ease when the projectile and tracer leave the muzzle of the gun and are relieved ot' the propelling charge gas pressure. 'lh'e plate need not be formed from the saine metal as the plug but may, it desired, consist of metal or material more suited to'the thermal function required of it. A perforated disk or washer cx may be provided to partially cover the forward face of the material (ordinarily more readily ignitible material) in pocket C", but it will be understood that if' this material is of such composition that it is not likely to become displaced or loose, this washer may be omitted. rlhe material of which the washer is made is unimportant; it may be of combustible or of readily fusible or ot' heat a'csisting material. ln this construction the plug is held in position in the mouth of the tracer chamber by screw threads F, and when the projectile and tracer leave the muzzle of the gun the presof an ignition'temperature -the material may be such that the penetration of -heat to it through the above nien--` tioned heat conductive wall will cause itll lfor the smoke and flame ot the burning tracer material.

In the modification shown in Fig. 8, the readily ignitlblc material 1n the recess oi' pocket C,1s contained in a metal cup C,

which may be held in position in any suit-A able way; for example; in the saine way as the cover 'plate c@ in Fig. 2. is held.

The modification shown in Fig. is similar to that shown in Fig. l. excepting` that a washer c* is provided as in lFig. 2. and that the wall c is so shaped as to proifide an extended surface for Contact with the propelling charge gases.

In the modification shown in Fig. 5. closure for the .mouth of the cell or 'chainber B is in the form' of a cap, and the pocket C isin the form of a hollow protuberance, presenting an extended surface for contact to the propelling charge gases- Although l have described several`einbodiments of the invention in which a recess or pocket in the plug or cap at the month of the tracer chamber contains readily ignitible material. the recess or pocket need not necessarily contain material dcpendent for its action upon the attainment to become operative without igniting; in the construction shown in Fig. (3, for instance, the material 1s a liquid inclosed in a glass or other case D fitting into the recess orA pocket, the nature of the liquid and its relation to the tracer material or to supple' ln all' forms of the tracer it will be understood that the thickness of the wall screening the tracer material or .adjacent supplementary material `from vdirect contact with the propelling charge `fases is dependent upon the conductivity of the material of which it is'composed andV the rapidity with which it is desired to raise the temperature of the said tracer material or til-acer-igniting material;

The. plug or cap itselie may be held in or upon the mouth of the tracer chamber or cell in any convenient manner, depending upon For example,I

ies j llt? 'f1-,reactie the degree of security desired. For example,

merely by friction, .as shown in. Figs. 3, 4,' 5 and ll; by a fill-ing of lead r cement as shown at E in Fig. l; by a set screw as shown in Fig. 9, capable of being sheared when the gun is fired; or by screw threads as already described in connection with Fig. Alternatively, as shown in Fig. 8, the plug may bekept in position by a resilient split ring H capable of receding into a recess H in the wal-l of the tracer chamber when the plug is being thrust into position and of ultimately springing forward into a circumferential groove on the plug. the plug is being blown out rearwardly from the mouth of the chamber', this locking ring either sheared or is forced back into the recess H. A spring li, as shown, may if desired be provided to hold the plug firmly 5 in position and assist in its expulsion from 'i the flared edge of which isradapted to spring into locking engagement with a` circumferential notch J in the wall of the tracer chamber at the mouth thereof. A spring K may be provided to keep the pluglgrmly in contact with the locking disk. n this figure the recess or pocket C in the plug U is shown open at the rear, and the central part of the' locking disk J servesias the inclosing conductive wall; whereas, in' the modification shown in Fig. 7a, the wall at the rear of the recess or pocket is integral with the plug, and the locking disk J has central perforation to enable the propelling charge gases to make direct contact with the wall. In the construction shown in Fig. 7 it will be un derstood that, when the gun is fired, the gas pressure will cause the locking disk and the plug to be pressed some distance into the mouth of the tracer chamber against the opposition of the spring, thereby causing the locking disk to become disengaged from the notch J and its flared edge to become contracted, so that when the projectile leaves the gun the plug will be free to be blown out of the mouth of the chamber, taking the locking disk with it. In F ig. 8 also the plug (l will first be driven forward toward the charge of tracer material and subse quently expelled.

It is to be observed that in the construc= tions shown by Figs. 1 to G the propelling charge gases are able to make direct contact with the whole rear surface or" the'plug,

whereas .in Fig. 7a they are able to make didisk J at the rear of the plug, but in the first instance they are directed through a nozzle L in aA protective disk M so as to impinge on the heat conductive wall constituted by the central part of the disk J, and thus the heating is intensified and localized.

In Fig. 10a I show further refinements of the structure of Fig. 10, which present conditions of service suggest. As in Fig. 1.0,the hole in disk M affords a blow-pipe efect, concentrating the'inrush of highly heated gases upon the center of copper plate J. This copper disk J, in turn, rests against plug C, with an interposed centrally perforated heat 'insulating disk R (which may be of paper) arranged between. The copper plate J is heavy enough to stand the preissure ofthe impinging stream of gases. The recess C in the plug C is filled preferably with such a readily ignitiblematerial as the following compound: fulminate of mercury,V

10% g chlorate of potassium, 20% and black powder, As indicated in Fig. l0, a space is preferably left between the pellet of readilyignit-ible material in pocket C and the rear face of the body of tracer material.

lt may happen that pieces of the wadding or spacing disk sometimes inserted in the cartridge case between the projectilennd the propelling charge may be crushed or otherwise forced against the base of the projectilii when the gun is fired, thereby preventing free access of the propelling charge gases to the above described heat conductive wall at the mouth of the tracer chamber, and thus as it wereinsulating the wall againstthe desired heating effect. In order to prevent such an occurrence, the tracer chamber may be provided at its base with a projecting skeleton framework or other means, adapted to shield the space immediately to the rear, of the mouth of the tracer chamber so las to prevent this space from ,becoming tracer, the framework N will serve to shield the thin wallv c, and thereby insure that the propelling charge gases shall have free access to' the4 thin wall. The said framework may be. integral with the tracer stock or be screwed or otherwise secured thereto.

I claim as my invention: l

l. lA projectile provided with a tracer chamber and means for protecting a body of tracer lmaterial within lsaid chamber from the contact of. gases generated on firing the projectile from a gun.v such means constituting a heat-conducting medium between I chamber,

such gases ot tiring and such body of tracer material and aording heat transmission in ignition-producing quantity.

2. A, projectile provided with a tracer chamber opening through its posterior face and a screen arranged yin the mouth oit said chamber; such screen being impenetrable to the gases generated on the tiring of the projectile from a gun but being heat conductive and affording heat transmission from such gases of liring to a body of tracer material within said chamber in ignition producing quantity.

3. A projectile provided with a tracer chamber and a closure for said chamber, said closure being heat conducting and affording transmission of heat in ignitionproducing quantity from the gases generated on the firing of the projectile from a gun to a body of tracer material within said chamber, said closure beiiig furthermore removable during the flight of' the projectile from its position by gas pressure consequent uponignition fot' a body of tracer material within said chamber.

4. rlhe combination of a projectile having atracer chamber opening through its pos terior face, a heat-conducting closure for said chamber affording ignition to a body of tra :er material within said chamber by heat communicated from thegases of iring, and a fender for said heatconducting ignitiona'ording closure.

The combination of a `vided with an outwardly opening tracer a closure for saidjchamber, a body projectile prorle/aces of ltracer material Within said chamber, body of ignitible material arranged Within4 said chamber, adjacent vsaid closure, and intermediate between said closure and said.

of heatconductingmaterial and aiording when the projectile is fired from a glimthe transmission of heat in ignition-producing `quantity from the gases of firing to a body of tracer material within said chamber, and a perforate disk arranged in the vmouth 'of said chamber external of and at'an interval from said closure. i

7. The combination of a projectile-provided with a tracer chamber and a closure arranged in the mouth ovtsaid chamber, said closure and the wall of said tracer chamber provided -With interlocking portions preventing displacement under normal oonditions7 such interlocking being however destructible by forces released on the tiring of the projectile from a gun.

In testimony whereof I have hereunto set my hand.

SAMUEL D. CUSHNG. lVitnesses BAYARD H. CrfnIsTY, FRANCIS J. ToMAssoN. 

